A catalyst system consisting of an organoaluminum compound and an organophosphine has been used to copolymerize an alkene oxide with an acrylate. An organoaluminum compound with zinc acetylacetonate has been employed to polymerize an alkene oxide.
Needed, however, have been methods and catalyst systems to provide products of increased molecular weight and of higher inherent viscosity, to favor the formation of rubbery solids rather than viscous liquids, in the polymerization of alkene oxides, of vinyl monomers, or copolymers thereof. While viscous liquids, where reactive groups are available, may be transformed into solid products by crosslinking, it is oftentimes more desirable to obtain a high molecular weight polymer to start with, without crosslinking, since it is thus possible to obtain better processibility and more desirable physical properties such as tensile strength, degree of elongation, modulus, and the like.